[The D Bug Tracker] "File does not exist" FileException on c:\hiberfil.sys

[dlangBugzillaToGithub]

vital.fadeev reported this on 2020-10-04T06:53:46Z

Transfered from https://issues.dlang.org/show_bug.cgi?id=21289

Description

Created attachment 1805
file

"File does not exist" FileException on existent file: c:\hiberfil.sys


Source code:

import std.stdio;

void main()
{
    import std.file : DirEntry;

    writeln( DirEntry( "c:\\hiberfil.sys" ).isDir() );
}

I expected "false".

Not FileException.

Because "c:\\hiberfil.sys" is exist.

!!!There are attachements in the bugzilla issue that have not been copied over!!!

[dlangBugzillaToGithub]

vital.fadeev commented on 2020-10-04T07:30:13Z

I look into the std.file... function "existsImpl()"...

...
    version (Windows)
    {
        // http://msdn.microsoft.com/library/default.asp?url=/library/en-us/
        // fileio/base/getfileattributes.asp
        return GetFileAttributesW(namez) != 0xFFFFFFFF; // INVALID_FILE_ATTRIBUTES
    }
...

existsImpl() functions return "false" on file "c:\\hiberfil.sys".
Because INVALID_FILE_ATTRIBUTES.
It not correct? because file exists.

I tried several ways: GetFileAttributesW(), GetFileAttributesExW(), FindFirstFileW().


Working solution :

    WIN32_FIND_DATAW fd;
    auto hFind = FindFirstFile ( "c:\\hiberfil.sys", &fd );

    if ( hFind != INVALID_HANDLE_VALUE )
    {
        writeln( "[ OK ]" );
        FindClose( hFind );
    }

Of course solution above is a little slower than GetFileAttributes(), but work correct with .sys files.

I will suggest using "FindFirstFileW()" in the "std.file: existsImpl()"  there is no better solution yet.

[dlangBugzillaToGithub]

vital.fadeev commented on 2020-10-04T15:19:55Z

Created attachment 1806
std-file-dirEnrty-windows.patch

[dlangBugzillaToGithub]

vital.fadeev commented on 2020-10-04T15:20:06Z

I fix bug. 
Check the patch. 
I will be happy when it will be committed in next version.

std-file-dirEnrty-windows.patch

( see attached .patch in ticket )

[dlangBugzillaToGithub]

vital.fadeev commented on 2020-10-04T15:22:59Z

FindFirstFileW() can read attributes of system locked files.
I used it.

[dlangBugzillaToGithub]

vital.fadeev commented on 2020-10-04T15:28:53Z

Created attachment 1807
fixed std.file.exists()

Using FindFirstFile() for check file existens under Windows.
Because correct work with system locked files: like a c:\hiberfil.sys

[dlangBugzillaToGithub]

vital.fadeev commented on 2020-10-05T12:29:36Z

Created attachment 1808
fix std.file.exists and std.file.DirEntry Windows version for system locked files and Windows root paths

Latest version patch. Includes all previous patches.

fix: 
- std.file.exists
- std.file.DirEntry Windows version for system locked files 
- Windows root paths attributes